Synergistic effects of mechanical and environmental loading in stress corrosion cracking of glass/polymer composites

Abstract

Polymer matrix composites have become one of the most popular advanced materials in various industries due to their outstanding properties, appropriate cost, and various and easy manufacturing methods. Unidirectional glass fiber reinforced polymer composites were investigated in this study for use as insulators in power transmission lines. Synergistic effects of nitric acid exposure, applied tensile stress, and time were examined. Physical and electrical properties of composites including acid/water absorption and current leakage were evaluated. Regarding high voltage tests, a direct correlation was found between the amount of absorbed moisture and the leakage current. Mechanical tests, including tensile, flexural, and compressive strength were performed on glass fiber reinforced polymer composites. The composites were degraded because of the stress corrosion cracking as verified by scanning electron microscopy. Stress corrosion cracking damage affected the composites differently depending on their composition; it was measured by the number of fiber cracks, amount of metallic ion leaching from the fibers, and the reduction in mechanical properties of the composites.